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* Consultants cite weaker investor interest, low volatility
* Investor products, power and gas show biggest declines
* Banks' commodity businesses struggle, hit by regulations
LONDON, Aug 5 (Reuters) - Commodity revenue slid by about aquarter in the first half of the year at the top 10 investmentbanks, mainly due to lack of investor interest and placidmarkets, a consultancy said on Monday.
Banks have struggled in recent years with their commoditybusinesses, hit by increasing regulation and higher capitalrequirements in the wake of the global financial crisis.
"Commodities performance for Coalition index banks declinedby approximately 25 percent in 1H 2013 relative to 1H 2012," London-based industry analytics firm Coalition said in a briefstatement, without giving financial figures.
"This was mainly due to lower client activity and lack ofvolatility. On a relative basis, investor products and power andgas had the largest decline."
Wall Street investment banks typically do not break downtheir commodity revenue, preferring to cite it as part of thebroader fixed income, currency and commodity category.
Last year, investment bank Goldman Sachs took the topspot for commodity revenue, followed by JPMorgan Chase and Morgan Stanley, Coalition said in March.
The other banks Coalition tracks are: Bank of AmericaMerrill Lynch, Barclays, Citigroup,Credit Suisse, Deutsche Bank, RBS and UBS.
The 19-commodity Thomson Reuters-Jefferies CRB index has shed 4 percent so far this year.
